A known conventional information processing structure is described in Japanese Patent Laid-Open No. 2001-313386. The conventional information processing structure has quantum dots formed directly above the gate electrode of a metal oxide semiconductor field effect transistor (MOSFET), first and second information electrodes formed on the both sides of the quantum dots in an in-plane direction of the substrate in which the MOSFET is formed and a power supply electrode formed above the quantum dots.
The quantum dots are coupled to the gate electrode of the MOSFET and the power supply electrode by tunnel junction. In addition, each quantum dot is capacitively coupled to a corresponding one of the first information electrodes and a corresponding one of the second information electrodes.
In the conventional information processing structure, according to the potential of the first and second information electrodes, electrons migrate between the power supply electrode and the gate electrode via the quantum dots because of coulomb blockade. As a result, the potential of the capacitor formed between the information processing structure and the substrate varies.
Therefore, the conventional information processing structure compares the voltages applied to the first and second information electrodes by detecting the potential of the capacitor that varies with the potential of the two information electrodes.